SPRUJ64 September   2022

 

  1.   Abstract
  2.   Trademarks
  3. 1Key Features
  4. 2AM64x SKEVM Overview
    1. 2.1 Board Version Identification
  5. 3Functional Block Diagram
  6. 4System Description
    1. 4.1  Clocking
      1. 4.1.1 Ethernet PHY Clock
      2. 4.1.2 AM64x SoC Clock
    2. 4.2  Reset
    3. 4.3  Power Requirements
      1. 4.3.1 Power Input
      2. 4.3.2 USB Type-C Interface for Power Input
      3. 4.3.3 Power Fault Indication
      4. 4.3.4 Power Supply
      5. 4.3.5 Power Sequencing
      6. 4.3.6 SOC Power
    4. 4.4  Configuration
      1. 4.4.1 Boot Modes
    5. 4.5  JTAG
    6. 4.6  Test Automation
    7. 4.7  UART Interface
    8. 4.8  Memory Interfaces
      1. 4.8.1 LPDDR4 Interface
      2. 4.8.2 MMC Interface
        1. 4.8.2.1 Micro SD Interface
        2. 4.8.2.2 WiLink Interface
        3. 4.8.2.3 OSPI Interface
        4. 4.8.2.4 Board ID EEPROM Interface
    9. 4.9  Ethernet Interface
      1. 4.9.1 DP83867 PHY Default Configuration
      2. 4.9.2 DP83867 – Power, Clock, Reset, Interrupt, and LEDs
      3. 4.9.3 Industrial Application LEDs for Indication
    10. 4.10 USB 3.0 Interface
    11. 4.11 PRU Connector
    12. 4.12 User Expansion Connector
    13. 4.13 MCU Connector
    14. 4.14 Interrupt
    15. 4.15 I2C Interface
    16. 4.16 IO Expander (GPIOs)
  7. 5Known Issues and Modifications
    1. 5.1 Issue 1 - Silkscreen Missprint on Initial Board Batch
  8. 6Revision History

4.8.2.1 Micro SD Interface

The SKEVM board provides a micro SD card interface connected to the MMC1 port of the AM64x SOC. The micro-SD card interface supports 16 GB density with UHS1 operation including IO operations at both 1.8 V and 3.3 V. The circuit included in AM64x SoC to support the IO voltage switching is connected to IO voltage of SD signals to allow the processor to negotiate IO voltage. For high-speed cards, the ROM Code of SOC attempts to find the fastest speed that the card and controller can support and have a transition to 1.8 V. The internal SDIO LDO output from the SOC available at CAP_VDDSHV_SDLDO pin is connected to IO voltage of SD signals and VDDSHV_MMC1 power pins of SOC, which is the power supply for MMC1 interface.

An ESD protection device (TPD6E001RSE) is provided for data, clock, and command signals. TPD6E001RSE is a line termination device with integrated TVS diodes providing system-level IEC 61000-4-2 ESD protection, ± 8-kV contact discharge, and ± 15kV air-gap discharge.

The SD card is set to operate in SD mode. The CD (card detect) pin of SD card connector is pulled high and connected to the CD pin of the SOC. Figure 4-9 shows the block diagram of the micro-SD card interface.

GUID-D1A364A8-455C-435B-89DF-E41A99E0FF87-low.png Figure 4-9 Micro SD Interface